Here I am giving you question paper for NET Life Sciences examination in PDF file attached with it so you can download it easily..

Some questions are given below :

21. Which of the following bonds will be most difficult to break?
1. C–O
2. C–C
3. C–N
4. C–S
22. A solution of 1% (w/v) starch at pH 6.7 is digested by 15 µg of -amylase (mol wt
152,000). The rate of maltose (mol wt = 342) had a maximal initial velocity of 8.5 mg
formed per min. The turnover number is
1. 0.25 105 min–1.
2. 25 105 min–1.
3. 2.5 105 min–1.
4. 2.5 104 min–1.
23. The conformation of a nucleotide in DNA is affected by rotation about how many bonds?
1. 4
2. 6
3. 7
4. 3
24. Which of the following proteins acts as an energy transducer?
1. G-protein.
2. Bacteriorhodopsin.
3. Hemoglobin.
4. Heat shock protein.
25. Which of the following predicted property of lipid bilayers would result if the
phospholipids had only one hydrocarbon chain instead of two?
1. The bilayers formed would be much less fluid.
2. The diameter of the head group would be much larger than the acyl chain and would
tend to form micelles rather than bilayers.
3. the bilayers formed would be much more fluid.
4. the bilayers would be more permeable to small water-soluble molecules.
26. Which pump is responsible for initiating muscle contraction through depolarization of
muscle cell membrane?
1. Na+ pump.
2. K+ pump.
3. Ca2+ pump.
4. Mg2+ pump.
27. Which of the following statements is not true for transposable element system?
1. It consists of both autonomous and non-autonomous elements.
2. Dissociation elements are autonomous in nature.
3. Transposase is transcribed by the central region of autonomous elements.
4. Certain repeats in the genome remain fixed even after the element transposes out.
28. A set of virulence genes (vir genes), located in the Agrobacterium Ti-plasmid, is activated
by
1. octopine.
2. nopaline.
3. acetosyringone.
4. auxin.
29. When two mutants having the same phenotype were crossed, the progeny obtained showed
a wild-type phenotype. Thus the mutations are
1. non-allelic.
2. allelic.
3. segregating from each other.
4. independently assorting.
30. A conjugation experiment is carried out between F+ his+ leu+ thr+ pro+ bacteria and F– his–
leu– thr- pro- bacteria for a period of 25 minutes. At this time the mating is stopped, and the
genotypes of the recipient F– bacteria are determined. The results are shown below:
Genotype Number of colonies
his+ 0
leu+ 13
thr+ 26
pro+ 6
What is the probable order of these genes on the bacterial chromosome?
1. thr, leu, pro, his
2. pro,leu, thr and the position of his cannot be determined.
3. thr, leu, pro, and the position of his cannot be determined.
4. his, pro, leu, thr
31. Two varieties of maize averaging 48 and 72 inches in height, respectively, are crossed.
The F1 progeny is quite uniform averaging 60 inches in height. Of the 500 F2 plants, the
shortest 2 are 48 inches and the tallest 2 are 72 inches. What is the probable number of
polygenes involved in this trait?
1. Four.
2. Eight.
3. Sixteen.
4. Thirty two.
32. Repair of double strand breaks made during meiosis in the yeast Saccharomyces cerevisiae
1. occurs mostly by non-homologous end joining.
2. occurs mostly using the sister chromatid as a template.
3. occurs mostly using the homologous chromosome as a template.
4. is associated with a high frequency of mutations.
33. Which of the following signaling molecules enters the cell to initiate its action?
1. Transferrin
2. Insulin
3. Glucagon
4. Thyroxine
34. The mode of action of the anticancer drug methotrexate is through its strong competitive
inhibition on
1. dihydrofolate reductase.
2. thymidine synthase.
3. thymidine kinase.
4. adenylate cyclase.
35. Which class of immunoglobulins will increase in case of a chronic infection?
1. IgA
2. IgG
3. IgM
4. IgE
36. When prospective neuroectoderm from an early amphibian gastrula is transplanted in the
prospective epidermal region of a recipient (early gastrula) embryo, the donor tissue will
give rise to
1. neural tube.
2. epidermis.
3. neural tube and notochord.
4. neural tube and epidermis.
37. Amphibian oocytes remain for years in the diplotene stage of meiotic prophase.
Resumption of meiosis is initiated by
1. gonodatropic hormone.
2. growth hormone.
3. oestrogen.
4. progesterone.
38. A group of six cells called 'equivalence group cells' divide to form the vulval structure in
Caenorhabditis elegans. They are called so because
1. they have similar fates during development of vulva.
2. all the six cells are competent to form vulva and can replace each other under various
experimental conditions.
3. they are all under the influence of the anchor cell, signals from which initiate
vulval development.
4. they interact with each other to form the vulval structure.
39. Due to the presence of cellulose in the cell wall of plants, leaf shape is determined in the
leaf primorida by
1. rates of cell division.
2. planes of cell division.
3. cell migration.
4. cell-cell interactions.
40. DCMU inhibits electron transport in chloroplast by preventing the reduction of
1. P 680.
2. QA.
3. PQ.
4. QB.
41. In higher plant leaves, the reduction of nitrate to ammonium takes place by the combined
action of nitrate reductase localized in cytosol and nitrite reductase localized in
1. peroxisomes.
2. mitochondria.
3. chloroplasts.
4. cytosol.
42. In higher plants, the red/far-red sensory photoreceptor, phytochrome, is a light-regulated
kinase. Which of the following classes of kinases does it represent?
1. Two-component sensor regulator (histidine kinase).
2. Two-component sensor regulator (serine/threonine kinase).
3. Leucine rich repeat (LRR) receptor kinase.
4. Calcium-dependent protein kinase.
43. Vesicular-arbuscular mycorrhiza (VAM) represents a beneficial association between plant
roots and fungus, where fungus assists plants in obtaining from the soil
1. iron.
2. zinc.
3. sulphate.
4. phosphate.
44. Unidirectional propagation of electrical signal in nervous system is
1. proportional to the length of axon.
2. due to chemical synapse.
3. due to electrical synapse.
4. proportional to myelination.
45. A myasthenia gravis patient develops muscle paralysis because
1. the nerve terminal at the neuromuscular junction fails to release acetylcholine.
2. although enough acetylcholine is released at the neuromuscular junction, it is
destroyed by acetylcholinesterase.
3. the patient develops immunity against his own acetylcholine receptor.
4. the patient develops antibody against his own acetylcholine.
46. Inhibin from sertoli cells of testes selectively inhibits
1. luteinizing hormone.
2. follicle stimulating hormone.
3. thyroid stimulating hormone.
4. growth hormone.
47. Hawk's retina possesses a large number of
1. rods.
2. melanocytes.
3. cones.
4. kuffer cells.
48. E. coli cells were grown in N15 medium for several generations and then shifted to normal
medium for one generation. If the DNA isolated from the culture would be centrifuged on
a CsCl equilibrium density gradient, the result will be
1. a single band of double helix DNA consisting of one strand with N14 and another
with N15 label.
2. single band of double helix DNA consisting of N14 and N15 in both the
strands.
3. two bands containing double helix DNA each containing both N14 and N15 label.
4. two bands containing single stranded DNA one with N14 and other with N15
label.
49. Which of the following processes does not take place in the 5′→3′ direction?
1. DNA replication
2. Transcription
3. Nick translation
4. RNA editing
50. A deletion of three consecutive bases in the coding region of a gene cannot result in
1. deletion of a single amino acid without any other change in the protein.
2. replacement of two adjacent amino acids by a single amino acid.
3. replacement of a single amino acid by another without any other change in
sequence of the protein.
4. production of a truncated protein.
51. Deletion of the leader sequence of trp operon of E. coli would result in
1. decreased transcription of trp operon.
2. increased transcription of trp operon.
3. no effect on transcription.
4. decreased transcription of trp operon in the presence of tryptophan.
52. In the endodermis of higher plants, the role of Casperian strip is to control the water
movement so that it flows
1. between the cells.
2. through the plasma membrane.
3. through the cell wall.
4. through the transfusion tissue.
53. The reptilian order Squamata includes
1. crocodiles and alligators.
2. the living fossil 'tuatara'.
3. turtles and tortoises.
4. snakes and lizards.
54. Cultivated bananas are sterile because
1. male flower-bearing plants are very rare.
2. they lack natural pollinators in the crop plants.
3. they are triploid and therefore seeds are not set.
4. they are a cross of two unrelated species.
55. One life history trait that is not characteristic of very small sized organisms is
1. delayed age at first reproduction.
2. earlier age at first reproduction.
3. high population growth rate.
4. short lifespan.
56. Which of the following statements is the most appropriate example of character
displacement?
1. Two related species depending on the same prey species avoid competition by
feeding at different times of the day.
2. The body sizes of two related species are very similar when they are allopatric,
but in geographical areas of sympatry, one species is significantly smaller than
the other.
3. The food niche of a species is generally wider in the absence of competing species
than in their presence.
4. Closely related species can coexist if their densities are regulated by a predator.
57. In a population growing logistically and approaching Carrying Capacity (K), the
change in density (N) per unit time (dN/dt) is maximum when N equals to
1. K2
2. K/2.
3. K.
4. K.
58. The losses of ozone over Arctic are significantly lower than that over Antarctica
because
1. polar vortex over Arctic is not as tight as over Antarctic.
2. Arctic stratosphere warms slower in the spring.
3. concentration of chlorine in the atmosphere over Arctic is less than over
Antarctic.
4. freezing of NO2 and CH4 are slower over Arctic than over Antarctic.
59. Which of the following species replacement sequence depicts tolerance model of
community succession?
A B
C D
A B
C D
D
CD
A B
C D
A B
1
2
3
4
BCD
1 2 3 4 5 6 7 8 9 10
Trait value Trait value
1 2 3 4 5 6 7 8 9 10
60. Evolutionarily, with which of the following could parental care in animals be
associated?
1. Smaller clutch size.
2. Polygamy.
3. Greater longevity.
4. Semelparity.
61.
The change in a trait with time as a result of natural selection is shown above. This
type of natural selection is
1. directional.
2. disruptive.
3. stabilizing.
4. random.
62. During which geological period did the greatest diversification of life on earth occur?
1. Permian
2. Jurassic
3. Cambrian
4. Ordovician
63. Which of the following plant groups evolved during the Silurian period?
1. Bryophyta
2. Psilophyta
3. Lycophyta
4. Spherrophyta
64. Which of the following GM crops is the most widely cultivated globally?
1. Herbicide resistant soybean.
2. Insect resistant cotton.
3. Insect resistant brinjal.
4. delayed ripening tomato.
65. PCR based DNA amplification is an essential feature of which of the following
combination of molecular markers?
1. RFLP, AFLP and SSR.
2. AFLP, SSR and RAPD.
3. RFLP, RAPD and SSR.
4. RAPD, RFLP and SSR.
66. The genes whose promoters are extensively used for production of pharmaceutical
proteins in transgenic dairy cattles are
1. lactalbumin and ovalbumin.
2. lactoglobulin and casein.
3. lactoferrin and transferrin.
4. casein and ovalbumin.
67. A biochemist purifies a new enzyme, generating the following purification table.
S. No. Procedure Total protein
(mg)
Activity
(units)
i. Crude Extract 20,000 4,000,000
ii. Salt precipitation 5,000 3,000,000
iii. Ion-exchange
chromatography
200 800,000
iv. Affinity chromatography 50 750,000
v. Size-exclusion
chromatography
45 675,000
The most effective purification step is
1. iv.
2. iii.
3. v.
4. ii.
68. Similarities in sequence and function of two proteins indicate that they are members
of a family that share a common ancestor. If they are from different species, they are
called
1. homologs.
2. orthologs.
3. paralogs.
4. proteologs.
69. The conformation of a 30-residue peptide is studied by NMR spectroscopy. The JNH
for most of the amide protons is 4Hz. The 2D NOESY spectrum shows prominent
Ni-Ni+1 connectivities. The conformation of the peptide is
1. anti-parallel sheet.
2. parallel sheet.
3. helix-like.
4. unordered.
70. A sample of 32P disintegrates at a rate of 30,120 dpm. The radioactivity in
microcuries (1 curie=3.7x1010dps) is
1. 15,060.
2. 1.36x10-2.
3. 81.6 x10-2.
4. 1.36 x10-8.
PART C
71. A protein polypeptide chain exists in -helical conformation in a solvent and it has a
value of -30,000 deg cm2 dmol-1 for the mean residue ellipiticity at 222 nm ([ ]222) in the
temperature range 20-50C. On raising the temperature above 50C,[ ]222 increases and
reaches a value of -2,000 deg cm2 dmol-1 at 70C and the value of [ ]222 remains
unchanged above 70C. The observed value of [ ]222 is -14,000 deg cm2 dmol-1 at 60C.
If one assumes that the heat-induced denaturation is a two-state process, the fraction of -
helix at 60C is
1. 0.40
2. 0.43
3. 0.50
4. 0.57
72. 100 ml of 0.02 M acetic acid (pKa= 4.76) is titrated with 0.02 N KOH. After adding
some base to the acid solution, the observed pH is 2.76. At this pH degree of protonation
is
1. 0%.
2. 10%.
3. 90%.
4. 99%.
73. There are hydrogen bond donors (D), and acceptors (A). When the mixture (A+D) is
transferred from water, designated as (w) to a nonpolar solvent (np), the free energy
change (G) of transfer is 6.12 kcal mol-1 for the (A+D) mixture. A and D form a
hydrogen bond in this nonpolar solvent and G for this process is – 2.4 kcal mol-1. When
the hydrogen bonded molecule A-D is transferred from water to the nonpolar solvent G
for this process is 0.62 kcal mol-1. The value of G for the formation of hydrogen bond
(A+B  A-B) in water is
1. -0.1 kcal mol-1.
2. +3.1 kcal mol-1.
3. -3.1 kcal mol-1.
4. -1.78 kcal mol-1.
74. In a human cell, the concentration of ATP, ADP and Pi are 2.25, 0.50 and 0.825mM
respectively. The free energy of hydrolysis of ATP at pH 7.0 and 25°C is
1. –30.5kJ/mol.
2. –61kJ/mol.
3. –15.25 kJ/mol.
4. –52 kJ/mol.
75. Which one of the following enzyme reaction represents noncompetitive initiation?
1. E+S      ES + E + P
ES + I I K       EI
2. E+S      E+S E + P
ES + I
1 K
      ESI
3. E+S1      ES1      EʹP1 1 P       Eʹ 2 S         EʹS2 E+P2
4. E+S      ESE+P
E+S+I I K       EI + S
ES + I
I K
ESI
EI + S       ESI
76. The sequence of monosaccharides including position and configuration of glycosidic
bonds in a glycoprotein is to be determined. Which one of the following methods can be
employed?
1. Glycoprotein removal of oligosaccharides by alkaline
hydrolysis nuclear magnetic resonance analysis of cleaved mixture
of oligosaccharides
2. Two dimensional nuclear magnetic resonance spectroscopic analysis of
the glycoprotein
3. Glycoprotein release of oligosaccharides with endoglycosidases
followed by purification to separate oligosaccharides enzymatic
hydrolysis of purified oligosaccharides with specific
glycosidases mass spectroscopic analysis of smaller
oligosaccharides
4. Glycoprotein treat with trypsin followed by MALDI analyses of
tryptic peptides
77. A bacterial culture undergoing balanced growth requires a first-order reaction. In other
words, the rate of increase in bacteria at any particular time is proportional to the number
or mass of bacteria present at that time. If „N‟ is the number of cells at any given time „t‟
and „ ‟ is „growth rate constant‟ this process can be expressed mathematically as
1. N
dt
dN
.
2. N
dN
dt
.
3. N
dt
d


.
4. N
dt
dN
.
78. A typical animal cell (nucleated) membrane contains glycolipids and glycoproteins in the
plasma membrane. To determine its topological distribution, „lectin‟ is used as a probe.
The following interactions may be the basis of the probing method:
(A) Protein-protein interaction
(B) Protein-sugar interaction
(C) Protein-lipid interaction
(D) Protein-sterol interaction.
The appropriate answer is
1. Only (A).
2. Only (B).
3. All of (A), (B) and (C).
4. Only (D).
79. Upon studying a considerable number of different crosses in Drosophila, Morgan reached
the conclusion that all genes of this fly were clustered into four linked groups
corresponding to the four pairs of chromosomes. Further studies revealed that linkage is
not absolute and it is broken frequently. It is broken in prophase by a process called
1. Recombination.
2. Jumping of genes.
3. Integration.
4. Mutation.
80. A population of proliferating cells is stained with a DNA binding fluorescence dye so that
the amount of fluorescence is directly proportional to the quantity of DNA. Amount of
DNA in each cell is measured by flow cytometry. The number of cells with a given DNA
content is plotted and following statements were made:
(1) Peak A contains the cells of G1 phase
(2) Peak B contains the cells of G2 phase
(3) Peak A contains the cells of G2 phase
(4) Peak B contains the cells of G1 phase
Which of the above mentioned statement is correct?
1. (1) and (2).
2. (3) and (4).
3. (2) and (4).
4. (1 ) and (3)
81. During many important cell processes, many proteins need to undergo degradation to
culminate a part of the process. For example, during cell cycle, cycling proteins need to
be degraded to allow the cells to exit mitosis. This is achieved by selective ubiquitination
of cyclin followed by its degradation by proteasomes. The specific protein factor that is
involved in this process is called Anaphase Promoting Complex (APC). APC is possibly
a protein which is known as
1. E1 enzyme.
2. E2 enzyme.
3. E3 enzyme.
4. Protease.
82. During mitogenic stimulation, cells proliferate at a higher rate and it is primarily
determined by an enhanced rate of protein synthesis. Among other mechanisms, MAP
kinase pathway of signal transduction is involved in this. Global protein synthesis may be
regulated by many mechanisms involving various steps of protein synthesis, namely,
initiation, elongation and termination. Thus, many protein factors may be involved in the
same. In the above process (mitogenic stimulation) the following factors are the portable
targets.
A. elF -2
B. eEF-1
C. S6 kinase
D. elF-4E BP
The correct answer is
1. A+B
2. C+D
3. D+A
4. B+D
83. DNA repair, synthesis and recombination are intimately connected and inter dependent.
An apparent commonality between processes of DNA replication and repair in the
enzymatically catalyzed synthesis of DNA polynucleotide segments, which can be
assembled with preexisting polynucleotides, leading to repair or replication. Synthesis of
these polynucleotide segments is catalyzed by a group of enzymes DNA-dependant DNA
polymerases. In the case of E.coli, DNA polymerase has been isolated in three distinct
forms whereas five main types of polymerase have been isolated from mammalian cells.
All the polymerases synthesize polynucleotides only in the 5' 3' direction. If
polynucleotide chains could be elongated in 3'5' direction, the hypothetical growing 5'
terminus, rather than the incoming nucleotide, would carry a triposphate that is unsuitable
for further elongation. The 3' 5ʹ exonuclease activity is not associated with all the
polymerases and only present in
(A) All E. coli DNA polymerases but not all mammalian polymerases.
(B) Pol I, Pol II, Pol III, Pol , Pol .
(C) Pol I, Pol II, Pol , Pol, Pol 
(D) Pol I, Pol II, Pol, Pol .
The correct statements are
1. (A) and (B).
2. (A), (B) and (C).
3. (A) and (C).
4. (A), (C) and (D).
84. Bacteriophage genetic circuit may be represented as follows:
The control of gene expression occurred during the phage infection may be described as
follows:
(A) N and Q protein act as antiterminator
(B) CI acts only as repressor
(C) CII act as a retroregulator
(D) CI and CII both act as positive and negative regulator
Which one of the statements are correct?
1. (A), (B) and (C).
2. (B), (C) and (D).
3. (A) and (D) only.
4. (A), (C) and (D).
85. Rho factor is involved in termination of transcription in prokaryotes. Genetic
manipulations indicate that Rho-dependent termination requires the presence of a specific
recognition sequence on the newly synthesized RNA upstream of the termination site.
The recognition sequence must be on the nascent RNA rather than the DNA, as
demonstrated by Rho‟s inability to terminate transcription in the presence of pancreatic
RNAse. The essential features of this termination site have not been fully elucidated.
Construction of synthetic termination sites indicates that it consists of 80 to 100 nts that
lack a stable secondary structure and contain multiple regions that are rich in C and poor
in G.
Which of the following is/ are suggested by the above observation?
1. Rho factor attaches to nascent RNA at its recognition sequence and then
migrates along the RNA in the 5131 direction until it encounters an RNAP
paused at the termination site.
2. Rho unwinds the RNA-DNA duplex forming the transcription bubble, thereby
releasing the RNA transcript.
3. Rho factor attaches to the RNA at its recognition sequence while RNA is in the
RNA-DNA hybrid condition.
4. There may be other factors and hence Rho factor does not need to unwind the
RNA-DNA hybrid to release the transcript.
86. During development and differentiation, there is a dynamic programme of differential
expression of sets of genes. In bacteria, phage infections are among the simplest
examples of developmental process. Typically, only a subset of the phage genome, offer
referred to as immediate early genes, are expressed in the host immediately after phage
infection. As time passes, early genes start to be expressed, and the immediate early
genes and bacterial genes are turned off. In the final stage of phage infection, the early
genes give way to late genes. One of the simplest way it is achieved is through
(A) expression of cascade of factors
(B) expression of new RNA polymerases
(C) expression of different holoenzymes
(D) expression of different transcription factors
The correct reasons are
1. (A), (D)
2. (A), (C), (D)
3. (A), (B), (D)
4. (A), (B), (C)
87. Polyclonal antibodies are raised against bovine serum albumin in rabbit. Subsequently
IgG in the antiserum is purified and digested with either pepsin or papain. Out of the
following possibilities, which one is correct?
1. Pepsin-digested antibodies cannot precipitate the antigen
2. Papain-digested antibodies cannot precipitate the antigen
3. Pepsin digestion will produce two Fab molecules
4. Pepsin-digested antibodies will lose all interchain disulfide bonds
88. Two protein kinases, K1 and K2 function sequentially in regulating intracellular pathway
in response to extracellular signal. The following observations are made:
(i) Response is observed even in the absence of extracellular signal when
a mutation permanently activates K1.
(ii) Response is observed even in the absence of extracellular signal when
K1 contains an activating mutation and K2 with inactivating mutation.
(iii) No response in the cells is detected even in the presence of
extracellular signal when both kinases are inactivated by mutation.
Which one of the following is correct?
1. K1 activates K2
2. K2 activates K1
3. K1 inhibits K2
4. K2 inhibits K1
89. Conversion of proto-oncogene to oncogene may involve the following processes:
A mutation in coding sequence
B gene amplification
C chromosome rearrangement
D mutation in non-coding sequence
Which one is appropriate?
1. A, B and C
2. B, C and D
3. A, C and D
4. All
90. Opsonisation of a bacterium is a process by which specific antibody binds with the
surface molecule of the bacteria. In an experimental condition, macrophage were infected
with either WT: Mycobacteria or with opsonised: Mycobacteria for 2 hrs at 37C.
Subsequently, cells were washed and further incubated for 24 hrs at 37C. Finally,
bacterial load in macrophages were determined by colony forming unit (CFU). Which of
the following observation is true?
1. WT:Mycobacteria inhibits its transport to the lysosomes and survive
in macrophages.
2. Opsonised: Mycobacteria inhibits its transport to the lysosomes and
survive in macrophages.
3. WT: Mycobacteria are targeted to the lysosomes and killed in
macrophages.
4. Opsonised: Mycobateria are targeted to the lysosomes and survive in
macrophages.
91. Which of the following cannot be used for determination of tissue lineage of a given
progenitor cell population in an animal?
1. Marking progenitor cells with vital dye.
2. Transplanting equivalent progenitor cells from immunologically
distinct but related organism.
3. Marking progenitor cells by genomic recombination coupled with
reporter gene expression.
4. Marking progenitor cells by reporter gene expression under the control
of a promoter – enhancer element specific for the given progenitor
population.
92. During vertebrate limb development, a specialised ectodermal structure, called Apical
Ectodermal Ridge (AER), forms at the dorso-ventral ectodermal boundary at the distal tip
of the developing limb bud.
The following experimental facts about the AER is available:
(A) FGF 2, 4, and 8 are expressed in the AER
(B) Removal of the AER causes cessation of limb growth
(C) Removal of AER along with implantation of beads soaked in FGF 8 or
(D) FGF 4 or FGF 2 protein rescues the AER removal phenotype and gives rise to
normal limb
Which of the following statements cannot be made based on the above facts?
1. FGF 2, 4, and 8 are secreted proteins.
2. FGF 2, 4, and 8 are necessary and sufficient for AER function
3. FGF 2, 4, and 8 are sufficient for AER function
4. FGF 2, 4, and 8 have largely redundant functions
93. During fertilization in amphibians, the fusion of egg and sperm plasma is preceeded by
(A) release of enzymatic contents from the acrosomal vesile through exocytosis
(B) binding and interaction of the sperm to vitelline membrane
(C) chemoattraction of the sperm to the egg by soluble factors secreted by egg
(D) passage of sperm through extracellular envelope
Which of the following is the correct sequence?
1. (A) (B) (C) (D)
2. (B) (A) (C) (D)
3. (C) (A) (B) (D)
4. (C) (B) (A) (D)
94. In many different contexts of cell differentiation, two distinct cell populations emerge
from a uniform cell population. This process is referred to as lateral inhibition. Which
one of the following must not be true about lateral inhibition?
(A) lateral inhibition results from morphogen action
(B) lateral inhibition requires direct cell cell contacts
(C) lateral inhibition requires reciprocal signalling between two
neighbouring cells
(D) lateral inhibition is preceded by stochastic changes in gene expression in two
neighbouring cells
1. (D)
2. (A) and (D)
3. (B) and (C)
4. (A)
95. Which of the following statements is true about dorso-ventral patterning of
drosophila embryo?
(A) This is dictated by the location of the nurse cells
(B) dorsal is the default fate
(C) The whole process is regulated by preventing the entry of a transcription factor to
the nucleus of dorsal cells
(D) Homeobox containing genes play a critical role in this process.
1. (A), (B) and (C)
2. (A),(B), (C) and (D)
3. (A) and (D)
4. (B) and (C)
96. Which of the following is true about amphibian limb regeneration?
(A) It requires a minimum number of functional nerves.
(B) The blastema of an amputated limb, if transplanted in the trunk region
between two existing limbs in a host, will still give rise to a limb.
(C) The size of the regenerated limb is often grossly different from the
original limb.
1. (A)
2. (B) and (C)
3. (A) and (C)
4. (A), (B) and (C)
97. In agamous mutant (flower within flower phenotype) which of the following
statements is valid?
1. Class A genes are expressed in the first two whorls, Class B genes are
expressed in the second and third whorls and Class C genes are
expressed in the third and fourth whorls.
2. Class A genes are not expressed. Class B and C genes are expressed
in all the whorls.
3. Class A genes are not expressed. Class B genes are expressed in the second and
the third whorls and Class C genes are expressed in all the whorls.
4. Class A genes are expressed in all the whorls. Class B genes are
expressed in the second and the third whorls.
98. Plants grown in greenhouse at 25°C when exposed first to 35°C for 6 hours and
subsequently to 42°C for 12 hours adapt better to the high temperature (42°C) in
comparison to those directly transferred to 42°C for the same duration. What is the
phenomenon called and what is its main physiological basis?
1. Acquired thermo-tolerance because of the induction of mutagens
resulting into improved stability of all the proteins.
2. Induced thermo-tolerance because of the induction of heat shock proteins.
3. Induced thermo-tolerance because changes in RNA polymerase II resulting in
efficient and improved transcription.
4. Acquired thermo-tolerance because of efficient post translational
modification of proteins.
99. In which molecule would the radiolabel appear the earliest when wheat and sugar cane
leaves are fed with 14CO2?
1. Wheat – malate, sugarcane – 3phosphoglycerate.
2. Wheat – aspartate, sugarcane – malate.
3. Wheat – 3phosphoglycerate, sugarcane – 3phosphoglycerate.
4. Wheat – 3phosphyoglycerate, sugarcane – malate.
100. A young dicot seedling (e.g soyabean) is subjected to gravity stimulus by laying it
horizontally on a surface the shoot bends upwards and root bends downward. Indicate
the reason.
1. Redistribution of auxin throughout the seedlings is responsible for stimulatory
unequal growth in shoots and roots.
2. Redistribution of auxin in shoots while cytokinine in roots is responsible for
stimulatory unequal growth.
3. Redistribution of auxin in roots while cytokinine in shoots is responsible for
stimulatory unequal growth.
4. Redistribution of cytokinine throughout the seedlings is responsible for
stimulatory unequal growth in shoots and roots.
101. Which of the following statements are associated with the process of
photorespiration in plants?
(A) Photorespiration takes place in only C3 plants.
(B) Photorespiration takes place in only C4 plants.
(C) Photorespiration takes place in both C3 and C4 plants.
(D) Glycolate is oxidized to glyoxylate in the peroxisome.
(E) Glycolate is oxidized to glyoxylate in the mitochondira.
1. (A) and (D)
2. (C) and (D)
3. (B) and (E)
4. (C) and (E)
102. Aspartate kinase is a key enzyme in the lysine amino-acid biosynthesis in plants. With an
objective of increasing the lysine content in maize seeds, maize plants were transformed
with E.coli aspartate kinase with a strong seed specific plant promoter. Resulting
transgenic plants were found to express the transgene; however, the content of lysine did
not increase. Which of the following option best explain the possible reason?
1. Bacterial proteins are not stable in plants.
2. Bacterial proteins are not properly folded in plants.
3. Proper post-translational modification did not take place in plants.
4. Lysine causes feed back inhibition of aspartate kinase
103. Electrical stimulation of a nerve bundle maintained at 37 + 10C showed A, B, C and D
peaks (as shown in the diagram) when recorded at a distance of 15 cms from the
stimulating site on the same bundle. The same experiment was conducted at significantly
lower temperature 15 + 10C. Which of the following statements is correct?
Lower temperature would
1. not affect the record.
2. not show A, but would show B, C and D peaks.
3. not show peak D and may not show C, but would show A and B.
4. show all the peaks along with a new peak
104. A response was observed when a specific site in a rat brain was stimulated by passing
electrical pulses through indwelling electrode implanted surgically. In another experiment
in another rat, a cannula was surgically implanted instead of the electrode and stimulated
the area by injecting excitatory neurotransmitter. However, the result of the two
experiments did not match. The possibilities of variations in the results could be due to
1. animal variations only.
2. stimulation of cell bodies or nerve fibers only.
3. difference in anatomical brain areas only.
4. variations in all the reasons mentioned in 1, 2 and 3.
105. (A) In an experiment, 2mg of a substance 'A' dissolved in 4.5 ml sterile solvent
was injected as a bolus into the femoral vein of an intact frog. It was
observed that the frog's heart rate increased significantly.
(B) The same solution as in (a) when applied directly on the heart of the same frog
after exposing the heart, the heart rate did not change.
(C) The same solution as in (a) when injected to an intact cat femoral vein, the
heart rate did not change significantly.
From the above observations, which one of the following statements is most likely to be
correct?
1. Substance 'A' is stimulatory on heart and the effect was inotropic.
2. substance 'A' acted in the brain and also might have released other hormones to
increase the heart rate.
3. substance 'A' could not have acted on the brain but must have induced other
substances in the blood to increase the heart rate.
4. the increased heart rate was merely due to increased volume of the heart muscles.
106. In a healthy kidney given the following information:
(A) Glomerular hydrostatic pressure – 75 mm Hg
(B) Glomerular capillary colloid osmotic pressure – 40 mm Hg
(C) Hydrostatic pressure in the Bowman's capsule – 20mn Hg
The net filtration pressure will be
1. 55mn Hg.
2. 15 mn Hg.
3. 35 mn Hg.
4. 135 mn Hg.
107. Identical limb lead electrocardiograms from three adult subjects taken by the same
machine under identical conditions are shown in the figure. The X-Y scales should be
considered identical for all three electrocardiograms. Which of the following statements
is correct?
1. (a) and (c) are from normal individuals having normal hearts, while (b)
shows abnormal atrial repolarization.
2. (a) is normal, (b) ventricular defect while (c) abnormal propagation of
electrical waves through atrium only.
3. (a) is normal, (b) atrial depolarization is opposite to that of in a normal heart
and (c) shows local damage throughout the ventricle possibly due to
previous myocardial infarction.
4. (a) and (c) are from normal individuals, having normal heart, where as (b) is
from an individual with abnormal propagation of electrical waves through the
ventricle only.
108. Mismatch of blood in parents many result in erythroblastosis fetalis in a new born. Match
the correct cause (left column) and usual treatment (right column).
Commonest cause Used treatment
A. Mother Rh(+) and father Rh(-) C. replacement of neonate‟s blood
with Rh(-) blood.
B. Mother Rh (-) and father Rh (+) D. replacement of neonate‟s blood
with Rh(+) blood.
1. A and C
2. A and D
3. B and C
4. B and D
109. In a haploid organism, the loci A/a and D/d are 8 map units apart. In a cross Ad X aD,
what will be the proportion of each of the following progeny classes: (a) Ad (b)
Recombinants.
1. 92%, 8%
2. 46%, 8%
3. 92%, 4%
4. 46%, 4%
110. During an experiment, an investigator found that the cell line used are RecA –/–. What
could be the probable finding which led him to such observation?
1. Loss of recombination.
2. Showing aberrant all morphology.
3. Cells developed phagocytic properly.
4. Cells were aggregating.
111.
Find the pattern of inheritance of the trait showing incomplete penetrance from the figure
shown above.
1. Autosomal dominant.
2. Autosomal recessive.
3. Mitochondrial inheritance.
4. X-linked recessive.
112. Which of the following assumption support the Hardy-Weinberg Equilibrium?
1. Presence of Natural Selection.
2. Random mating.
3. Genetic Drift.
4. Assortative mating.
113. Which of the following illustrations explain the correct pairing preceeding recombination
between a chromosome (ABC•DEFG/ABC•DEFG) and its inverted homologue
(ABC•DGFE/ABC•DGFE). The dot in genotype represent the centromere.
114. In E. coli , four Hfr strains donate the genetic markers shown in the order shown:
Strain 1: F L K O Z
Strain 2: C Y A Z O
Strain 3: P D W C Y
Strain 4: P F L K O
All the Hfr strains are derived from the same F+ strain. What is the order of these
markers on the circular chromosome of the original E.coli F+ strain?
1. K O Z P D F L W C Y A K
2. F L K O Z P D W C Y A F
3. F L K O Z A Y C W D P F
4. F L K C Y A Z O W D P F
115. In a family, father is homozygous dominant (AA) for a gene A and his wife is
homozygous for its ressive allele (aa) showing albino phenotype. It was surprising that
their child showed the albino phenotype. Which of the following phenomenon can
explain the phenotype?
1. Nondisjunction
2. Uniparental Disomy
3. Gene conversion
4. All of the above
116. Which of the following characteristic differentiate Eubacteria from Archaebacteria?
1. Circular nature of chromosome.
2. Absence of nuclear membrane.
3. Presence of 70S ribosomes.
4. Presence of murein in cell wall.
117. Tropical semievergreen forests are found in the region having rainfall
1. > 3000 mm.
2. 2000 – 2500 mm.
3. 1200–2500 mm.
4. 800–1200 mm.
118. Presence of which of the following flora and fauna in Peninsular India is explained by
the Satpura hypothesis?
1. Chinese.
2. Malayan.
3. African.
4. Mediterranean.
119. Complete the following sentence using options given below the sentence as a, b, c, d
and e.
“Species are critically endangered when it is not endangered but is facing _________risk
of extinction in the wild in the _____________future”.
(a) high
(b) very high
(c) extremely high
(d) near
(e) immediate
1. a, a
2. b, c
3. c, e
4. c, d

May 13th, 2014 12:38 PM

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Life Sciences Papers Along With solutions

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